WRT54G - in office network

I what to add WRT54G to a my company network, a have 3 office on one floor where i cannot install network cable , so i want to use linksys just as access point , so users with laptop can connect to our lan and share files with user on regular PC and server.
Can I do this with WRT54G ?

This is my setup of network in office :
ADSL Modem connected to Check Point firewall , all pc have dns ip of check point PC, all pc are connected to 2003 servers with switch's.
I just want to use WRT54G to connect 4 laptop to local network because i cannot use network cable in this part of building.
So if someone can give me a some instruction how to setup WRT54G.
i install DD-WRT Firmware.
How to setup WRT54G to be link between this laptops and rest of network.